I just spent a while fighting an exception that was being thrown from within a .NET runtime-generated assembly—specifically from Microsoft.
I recently developed a new application on my local machine (in Visual Studio/C++ 2008), and then moved it into our source/revision control system at work, IBM/Rational ClearCase (cc). The new app uses some third-party libraries for which we only have DLLs (no source), so I checked those into ClearCase, too. Unfortunately, the first time I made any changes to the version in cc and tried to step through the app in the debugger, I was immediately presented with an unfriendly error and app termination:
Debugger:: An unhandled non-continuable exception was thrown during process load
along with some return code (0xc0000022).